A typical water jet pump operates in a pressure range of up to 60,000 psi. This limit is established by the availability of materials that will withstand pressure cycling without fatigue failures. A typical intensifier pump includes a cylinder pressed on by a fluid, normally oil. This cylinder drives a plunger which displaces a second fluid such as, water, in a compression chamber. The pressure of the fluid in the cylinder causes a force equal to the area of the cylinder multiplied by the pressure in the cylinder. The pressure in a compression chamber driven by a second plunger is raised to a ratio of the area of the cylinder divided by the area of the compression chamber. The output and input of the compressed fluid is regulated by intake and output check valves.
It is desirable that the cylinder within the compression chamber withstand high operating pressures. Cylinders are manufactured by imposing exterior compressive loads on an interior cylinder. This compression causes the interior wall to have a static compressive stress. Other techniques for achieving compressive stress include adding a hoop around the interior cylinder of smaller inside diameter than the outside diameter of the liner. This strain produces a compressive stress in the inner surface of the inside cylinder. Additionally, autofrettage is achieved by imposing a high pressure on the inner surface of a solid cylinder. A compressive stress is therefore applied on the inside of the cylinder wall.
A need has arisen for intensifier pump having an interior cylinder that can withstand increased pressures and cycling loads. Such a pump must be easy to manufacture and maintain.